The main objectives of the project are to determine the influence of dietary factors on pancreatic enzyme secretion and bile acid kinetics and, in particular, the role of dietary protein, dietary fiber and bile acids on the rate of degradation of pancreatic enzymes in the small intestine. Conscious rats with bile and pancreatic juice cannulas have secretions collected and continuously returned to the intestine by peristaltic pump. Pancreatic enzyme secretion and bile acid output are monitored by diverting 2-5 percent of the secretions for sampling. After recovery from operative trauma and restoretion of normal food intake (4-6 days post-operative) small intestinal contents are collected and analyzed for enzyme activities and bile acids. In each rat, pancreatic enzyme output in pancreatic juice will be compared to the total enzyme activity in the small intestinal contents under fed and fasted conditions, to obtain a precise measure of the rate of disappearance of pancreatic enzyme activity in vivo under physiological conditions.